Wing-strut fastening for aeroplanes



`lune 23, 1925'. 1,543,651

H. c. MUMMERT WING STRUT FASTENING FOR AEROPLANES Filed May 29. 1922 2 Sheets-Sheet l l .l l* @w IN VEN TOR. HA m/fy C, MUM/mer 'BY Maggi@ ATToR.

June 23, 1925. 1,543,651

H. C. MUMMERT WING-STRUT FASTENING 'FOR AEROPLANES Filed May 29. 1922 2 Sheets-Sheet, 2

IN V EN TOR. HA fawn/C, MUM/15er A TTORN Patented June 23, 1925.

UNITED STATES PATENT OFFICE.

HARVEY C. MUMMEBT, OF HOLLIS, NEW YORK, ASSIGNOR.

BY MESNE ASSIGNMENTS,

TO CURTISS AEROPLANE AND MOTOR COMPANY, INC., 0F GARDEN CITY, NEW

YORK, A CORPORATION OF NEW YORK.

WING-STRUT FASTENING FOR AEROPLANES.

Application tiled May 29, 1922.

To @ZZ 107mm .it may concern:

Be it known that I, HARVEY C. MUMMERT, a citizen of the United States, residing at Hollis. in the county of Queens and State of New York, have invented certain new and useful Improvements in IVing-Strut Fastenings for Aeroplanes, of which the following is a specification.

My invention relates to aeroplanes and more particularly to improvements in the manner and method of fastening strut ends to aeroplane wing structures.

An object of the invention is to so constructand relatethe elements comprised in the strut fastening means that said elements, for the major part, are entirely enclosed and completely hidden within the contines of the outer covering of the win A further object of the invention is to so relate the elements which enter into and forni a part of the wing structure truss that the stresses set up in the wing structure are carried directly to points along the neut'ralaxes of the wing beams.

In completely removing the elements comprised in the strut end fastening means from the line of airrush incident to light, ob viously the head resistance which such elements ordinarily otfcr is wholly eliminated; and in carrying the stresses set up in the wing structure to points along the neutral axes of the wing beams, obviously a stronger and lighter structure, other factors being equal, can be obtained.

In attaining the above objects I aim at the same time, to simplify the construction of the component parts of the strut fastening means and to so organize and relate such parts as to render all parts accessible, and it desired, visible; visibility being obtained by the use of transparent wing cover pieces in the immediate vicinity ot the strut ends.

Other objects vand advantages of the invention will be hereinafter pointed out.

In the drawings:

Figure 1 is a perspective View, with parts broken away, showing the strut end fastening and its relation to one of the wing beams of the win Figure 2 is a ront end elevation, partly broken away, further illustrating the strut rnd lfastening;

Figure 3 is a section `on the line .3--3 of r.Figure and,

Serial No. 564,357.

Figure 1 is a section on the line 4 4 of Figure 2.

In the embodiment of the invention selected for illustration, an aeroplane wing 10 of conventional profile is shown. Said wing is provided with the usual Vouter covering 1l, which may be, ot' sheet n'ietal, veneer. or fabric, and with two or more wing beams (but one ot which is shown) 12. Preferably the. wing beam 12 is of the box-beam type: i. e., is hollow throughout the major portion of its length, though the top and bottom cover pieces 13 may be, it' desired, dispensed with and deep and narrow boxbeani members 14, which in effect provide a continuous beam, used instead. IVhere the top and bottom pieces 13 are provided, an opening 15 is formed in the top cover piece. through which the elements which enter into and form a part of the wing struc ture truss extend. The openings 15 are required to be provided only in the Vicinity of the strut ends. In addition to the beams 12 and the outer covering 11 the wing 10 comprises ribs 16, compression members 17, and, if desired, internal brace wires (not shown). Such elements, excluding the covering 11, constitute the skeleton framework of the wing.

I'Vithin the hollow of the box-beam, or within the space between the beam members 14, the strut end fittings are disposed. Such fittings, but one of which is shown, are preferably so related to the wing beams as to concentrate the stresses set up in the wing structure at points alongl the neutral axes of the wing beams. The wing struts, which comprise a strut proper 17 and an outer streamline casing 18, are extended at their opposite ends beyond the outer covering 11 of the wing to enter the space between the beam members 14 orthe hollow of the boxbeam with which they, the struts, are assorxiated. On the opposite faces of the extended portion-ot the strut ends face plate 19 =`are provided, the plates in each instance being fastened to the strut ends by thrubolt-s 20.

Between the face plates 19 a substantially U shaped compression member 21 is disposed, the arms or extensions of said member being contiguous to the face plates with the bight portion in bearing contact with the end of the strut against which the face plates are secured. Together, the face plates and the compression member constitute a strong metal fitting by means of which the strut end is fastened to'the wing beam. Atpoints along the neutral axes of the wing beams pins Q2 are. disposed, each of the several pins. but one of which is shown, being extended through both bers of the box-beam and across the space therebetween. as well as through-the fitting of which the face plates 19 and the compression member 21 form a. part.. ln this manner the strut ends are held in place. To re-en'force the beam members at the points where the pins 22 are disposed. face plates 23 are provided. such plates being disposed on the opposite. faces of both beam members as illustrated in Figure 3. ln addition to the U shaped compression member 2l, each strut end is provided with a metal strap Q-l which is carried across the bight portion of the compression member and extended contiguous to the opposite faces of theA strut extension. whereby an a propriate. socket, for the strut end is former by the strap and tbe. face plates lf) collectively.

From the above description it will be observed that the strut ends enter the space between the beam members and that. the fittings provided on the ends of' the struts are not. only completely enclosed within the contines of the box-beam. but are necessarily enclosed within the. confines olf the. outer covering of the wing. Thus disposed. they are completely removed from the line of air rush incident to flight.. The brace wires for the wing structure, of which any number may be ]novided. are designated as 25. it.

and 9.7. The wires QG and 2T are carried directly to the fittings at. the str-ut ends.

Preferably such wires are. of streamline. section and at their ends are externally threaded. whereby in their assen'ibly they may be adjnstably fastened to the strut vend fittings. To receive the threaded ends of the brace wires QG and 2T, pins 29 and Q9 are provided. the pins being disposed on opposite sides of the pin 2Q and mounted to rotate. Each of such pins is `in turn provided with a threaded opening into which the threaded ends of the brace wires extend. Thus arranged. a very efficient and simple form of brace wire fast'- cning means is provided. rlhe brace wire 25. instead of being anchored. to the fitting by means of a rotatable pin. is fastened to an car 21)' formed by extending one. of the face plates 19 ofi in the direction of the wire length. Preferably the compression niember t7 of the wing framework is directly fastened as aty to the pin J2 which holds the st rut end in place.

rthat the strut end fasteningmeans may be '.xccessible. an opening 251 is Yformed in the wing covering in the vicinity of each strut end and if desired. such opening Si. upon the completion of theJ assembly of the wing beam mem-- structure, may be effeetually covered over by means of afsuitable transparency (not shown).` Thus organized, the fitting is visible for inspection purposes at all times.

A strut end fastening means characterized as above Set forth is especially adapted to the larger types of aircraft wherein box beams or hollow beams are desirable. there such fastening means is used, an except ional; ly clean joint is provided at the strut ends and all parts which considerable resistance to the forward travel ofthe.lmuhineare wholly removed from view. 'l`be disposition of the connections. at points along the neutral axis of the wing beams. is also desirable. for structural reasons as well as forreasons hereinbefore pointed' out.r B v .neutral,axis" is meant. m refer ring tolthe wing beams, that axis or point at which the tension and the compression stresses are equilibrated.

lVh-ilc l have described my invention in detail in its present preferred embodiment., it will be obvious to those'sliilled in the art after understanding my invention, thaty var4 ious changes and modifications may be made therein withoutl departing from the spirit or scope thereon. l aim in the appended claims to cover all such modifications and changes.

lVhat I claim is:-

l. ln an aeroplane, a supporting surface including in its structural framework a hollow beam, a wing strut, a fitting mounted on the end of the wing strut and enclosed for the major part within the hollow of said beam, and a pin extended across the. hollow beam at a point, along its neutral axis, said pin being in engagement with said fitting to provide a fastening means for the wing strut.

Qfln an aeroplane, ving strut, a hollow beam into the hollow of which one end of the wing strut is extended, a fitting mounted on the inside of the hollow beam to provide a fastening means for the wing strut, and a. pin extended across the hollow beam at a point along its neutral axis, said pin being extended through said fitting.

3. In an aeroplane, a wing strut, spaced beam members so related one to the other as to provide in effect. a continuous beam, a fitting mounted in the space between the beam members. said fitting being fastened to tht` wing strut.. a. pin extended across the space between said beam members to provide a. fastening for thestrut. end. and reenforcing plates provided onjthcl opposite faces of the beam members through wlnch said pin extends. i

4. ln an aeroplane. a. wing strut. a hollow beam into hollow of which one end of the wing strut is extended. a. fitting mounted on the inside of the'hollow beam to provide a fastening means for the wing strut. anchorages formed upon said fitting, brace would otherwise oti'erllt) wires fastened to said anehorages and likewise extend-ed into the hollow of said beam, and a pin extended across the hollow beam as a fastening for said fitting.

5. In an aeroplane, a wing strut, aA hollow beam into the hollow of which one of the wing strut is extended, a Htting mounted 'on the strut end extended into the hollow of said beam. brace wires anchored to said fitting and likewise extended into the hollow of said beam, opposed plates fastened against. opposite faces of said beam, and a, fastening pin for the stunt fitting extended thru said plates, thru said beam and across the hollowed-out portion thereof.

6. In an aeroplane, a hollow beam, a. strut extended at one end into thehollow of said beam, a fitting mounted on the enclosed strut anchored to said pins, and ar fastening pin y for the strut. fitting extended thru the beam at a point along its neutral axis.

7. ln an aeroplane, a Ahollow beam, a wing strut extended atl one end into the hollow of said beam, a fitting mounted on the enclosed strut end, a fastening pin extended across the hollow of said beam and thru said fitting, anchorages for brace wires formed upon said fitting. brace wires fastened to the anehorages and extended into the hollow of the beam, and an anchorage for a further brace formed upon one end of said pin.

Invtestimony whereof I hereunto aflix my signature.

HARVEY C. MUMMERT, 

